There's an article at Racialicious that does a good job of addressing why it matters who's in the lead role and why it's important that they've got it wrong. Why the Casting of The Hunger Games Matters.
This drama was one of the few entertainment-related things that made it through the noise of end-quarter period for me. I haven't read the book yet, though I've very much wanted to since one of my younger sisters recommended it. Given how popular it was, I wasn't surprised when I heard there was a movie version coming, and I made a note to myself to be sure to read it before the movie came out. So, not having read it yet, I don't have any real sense of who the characters are, or who might be right to play them, and I didn't have any idea why people were so upset about the casting. At first, I just kept reading that Jennifer Lawrence's hair and eyes were the wrong color, which seemed like nitpicking to me, given how frequently people wear dye their hair, or wear wigs and colored contacts. Then, I stumbled across a few things that mentioned what a big deal it was that Katniss doesn't look like her mom and sister, or that Katniss is compared to a character who is obviously not White, etc. "Ah," I thought, "I see your point." Then came the other shoe - I stumbled across a few really defensive posts about how it shouldn't really matter anyway, because it's all about class, and the world they're in is post-racial, and... That's where I stopped reading, because that's where people started shooting themselves in the foot, and I hate to see that happen. There are lots of issues to take up here, and they've been taken up by people far better situated to do so. What I'll say is this: if anyone can play grey-eyed, black haired Katniss, because race doesn't matter in Katniss' world, then why did the casting call specify that it only wanted "Caucasian"? Because that doesn't sound post-racial. Oh, I know - because, while the world of The Hunger Games might be post-racial (doubtful, but I'll see when I read it), ours is not. And that's why casting matters, and why it matters that Hollywood gets it wrong so often. We'll be watching this film in *our* world, where people are much more comfortable with the idea of casting a stereotypically blond-haired, blue eyed, fair-skinned actress in the role of an dark-haired, grey-eyed, olive-skinned character than they are with the idea of casting anyone even vaguely brown in the role of anything at all. Even a character from the same book, who is explicitly described as dark brown.
Again, not surprised. And, not having read the book and gotten attached, not disappointed in the way that actual fans are -- I'll get there when I've read it, and have my own ideas of what the characters should look like, which will inevitably not be what it translated to the screen. Instead, I'm disappointed the abstract way that I'm disappointed every time I hear that Hollywood never-ending quest to whitewash our imaginations continues.